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The Museum Telescope and the
Helen Sawyer Hogg Observatory

Who invented the telescope?

The discovery of the telescope is still being debated. It may have been Leonard Digges in 1570 or Hans Lippershey, a Dutch eyeglass maker in 1608. Lippershey called his invention kijkglas meaning looking glass. The military immediately recognized the usefulness of the telescope for watching battles and troops. Ship captains and sailors used it to look for land or other ships.

In 1609, Galileo Galilei, an Italian astronomer, first used the telescope to study the Moon, planets and stars. During the next few years, he improved the invention and renamed it, "telescopio", in 1611. The name comes from the Greek, tele meaning far away and skopeo meaning to look. Galileo's first telescope allowed him to see the surface of the Moon, the planet Venus, Jupiter's satellites, dark spots on the Sun, Saturn's shape and even the Milky Way and its million stars. The telescope made it possible to see objects not seen by the naked eye. Today, with telescopes, we can see almost to the edge of the universe.

How did the Museum acquire its telescope and observatory?

The telescope in the Museum's Technology Park comes from the Dominion Observatory formerly situated on the Central Experimental Farm property. It opened in 1905 and closed operations on April 1, 1970. In 1905, $310,000 was spent on the observatory, smaller buildings and a library, including equipment for astronomy, gravity, geomagnetism and seismology research. Also, the installation housed the Geodesic Survey and the International Boundary Commission. The observatory was used for astronomical research and public educational programmes. In July 1974, the telescope was moved to a new observatory at the National Museum of Science and Technology.

Who was Helen Sawyer Hogg?

The Museum dedicated its observatory to Helen Sawyer Hogg in 1989 for her work in astronomy. This remarkable woman was born on August 1, 1905 in Lowell, MA and died January 28, 1993, in Richmond Hill, ON. In 1910, she saw Halley's Comet, an event that sparked her fascination for astronomy. Helen Sawyer studied astronomy at Mount Holyoke College, receiving her doctorate in 1931 at Radcliffe. For several years, she worked alongside her husband, astronomer Frank Hogg. In 1935, Helen became an employee of the Dunlap Observatory in Richmond Hill, ON. Among her many achievements, Dr. Helen Sawyer Hogg taught astronomy at the University of Toronto. She wrote a weekly astronomy column to the Toronto Star and a book called "The Stars Belong to Everyone". Over the years, Dr. Hogg received many awards including the Order of Canada (officer) in 1968, (companion) in 1976. The asteroid 2917, discovered in 1980, was named Asteroid Sawyer Hogg in 1984. Helen Sawyer Hogg contributed to the advancement of astronomy and was world renowned for her research on variable stars.

The Telescope: Technical Information

The telescope is a 15 inch (38cm) refractor. The original lens was a 15-inch doublet (two-component lens system) which is in the Museum's collection. In 1958, the world's largest three component lens system (apochromat) replaced the double lens system. J.A. Braschear Co., of Allegheny, PA manufactured the original lens and Perkin-Elmer Corporation of Norwalk, CT, the current lens. The focal ration of the telescope is f/15 in a tube length of 225 inches (5.7m). The telescope axis is at an angle of 45 degrees, the latitude of Ottawa. Warner and Swasey Company of Cleveland, Ohio manufactured the telescope mounting and the original driving mechanism, a conical pendulum clock. Electricity drives the telescope now.

For further information on telescopes and Helen Sawyer Hogg visit Science Information or the library at the National Museum of Science and Technology.



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